package Day12;

import java.util.ArrayList;

public class Demo01 {
    public static void main(String[] args) {
        //ArrayList:  使用的是数组结构，增删慢，查找快
        ArrayList<Integer> list = new ArrayList<>();
        list.add(5);
        list.add(6);
        list.add(7);
        System.out.println(list.get(0));
        System.out.println(list.size());
        System.out.println(list.remove(0));
        System.out.println(list.get(0));
    }
}
